An image forming apparatus includes an apparatus body, an image bearing member, and a process unit attached to the apparatus body, the process unit including a frame including a storage portion configured to store developer, a developer bearing member configured to supply developer to the image bearing member to develop an electrostatic latent image; and a circuit board attached to the frame, wherein the circuit board includes a light emitting portion configured to emit light, and a light receiving portion configured to receive the light emitted from the light emitting portion and having passed through an interior of the storage portion.

A toner conveying apparatus includes a frame body, a conveyance member, a light transmission portion, a light emission portion, a light reception portion, and a rubbing member. The frame body forms a conveyance passage surrounded by a wall portion and is provided with a reception inlet for receiving toner from outside. The conveyance member is provided in the conveyance passage and rotates around a first rotation axis to convey the toner. The light transmission portion that is provided in the wall portion and has translucency. The light emission portion emits light toward an inside of the conveyance passage through the light transmission portion. The light reception portion receives the light emitted from the light emission portion through the light transmission portion. The rubbing member rubs on the light transmission portion by being rotated around a second rotation axis extending in a direction crossing the first rotation axis.

A toner level detector, includes: a toner cartridge storing toner and having one side provided with a light-permeable region; an agitator, which is rotatably disposed in the toner cartridge and agitates the toner; a reflective region disposed on an inner surface on the other side of the toner cartridge; a first cleaner disposed on one side of the agitator; a second cleaner disposed on the other side of the agitator; and a transceiver, which is disposed on a body outside the toner cartridge, and outputs an emitting signal to the reflective region through the light-permeable region, wherein the reflective region reflects the emitting signal to generate a reflective signal received by the transceiver through the reflective region, wherein the first cleaner, which is rotating, intermittently cleans the light-permeable region, which is fixed; and the second cleaner, which is rotating, intermittently cleans the reflective region, which is fixed.

A toner conveying apparatus includes a frame body, a conveyance member, a light transmission portion, a light emission portion, a light reception portion, and a rubbing member. The frame body forms a conveyance passage surrounded by a wall portion and is provided with a reception inlet for receiving toner from outside. The conveyance member is provided in the conveyance passage and rotates around a first rotation axis to convey the toner. The light transmission portion that is provided in the wall portion and has translucency. The light emission portion emits light toward an inside of the conveyance passage through the light transmission portion. The light reception portion receives the light emitted from the light emission portion through the light transmission portion. The rubbing member rubs on the light transmission portion by being rotated around a second rotation axis extending in a direction crossing the first rotation axis.

A toner level detector includes a toner cartridge, an agitator, a reflective region, a first cleaner, a second cleaner and a transceiver. The toner cartridge stores toner, and has a light-permeable region. The agitator rotatably disposed in the toner cartridge agitates the toner. The reflective region is disposed on the agitator. The first cleaner is disposed on the agitator. The second cleaner is disposed on the toner cartridge. The transceiver disposed on a body outside the toner cartridge outputs an emitting signal to the reflective region through the light-permeable region. The reflective region reflects the emitting signal to generate a reflective signal received by the transceiver through the reflective region. The rotating first cleaner intermittently cleans the fixed light-permeable region, and the fixed second cleaner intermittently cleans the rotating reflective region.

A powder storage height detection device includes: a main body that includes a transport path along which powder is transported; a powder transport unit that is disposed to rotate in the transport path and includes a transporter provided spirally around a rotational shaft; a swinging unit that comes into contact with a surface of the powder transported in the transport path, and swings by following at least a storage height of the surface; a detection unit that detects a state of swinging of the swinging unit; and a determination unit that determines presence or absence of the powder based on a detection signal outputted from the detection unit. The transport unit includes a non-transport portion in which the transporter is not present, and which is formed as an eccentric shaft having a shaft center displaced from the rotational shaft, the swinging unit is located and disposed to swing in the non-transport portion, and the determination unit samples the detection signal at an interval, and when a proportion of the detection signal lower than or equal to an output level becomes greater than or equal to a threshold value, outputs a signal indicating determination of absence of the powder, the interval being obtained by dividing a required time for one rotation of the transport unit by a predetermined number, the output level defining that the storage height is relatively low.

A powder storage height detection device includes: a main body that includes a transport path along which powder is transported; a powder transport unit that is disposed to rotate in the transport path and includes a transporter provided spirally around a rotational shaft; a swinging unit that comes into contact with a surface of the powder transported in the transport path, and swings by following at least a storage height of the surface; a detection unit that detects a state of swinging of the swinging unit; and a determination unit that determines presence or absence of the powder based on a detection signal outputted from the detection unit. The transport unit includes a non-transport portion in which the transporter is not present, and which is formed as an eccentric shaft having a shaft center displaced from the rotational shaft, the swinging unit is located and disposed to swing in the non-transport portion, and the determination unit samples the detection signal at an interval, and when a proportion of the detection signal lower than or equal to an output level becomes greater than or equal to a threshold value, outputs a signal indicating determination of absence of the powder, the interval being obtained by dividing a required time for one rotation of the transport unit by a predetermined number, the output level defining that the storage height is relatively low.

A toner level detector, includes: a toner cartridge storing toner and having one side provided with a light-permeable region; an agitator, which is rotatably disposed in the toner cartridge and agitates the toner; a reflective region disposed on an inner surface on the other side of the toner cartridge; a first cleaner disposed on one side of the agitator; a second cleaner disposed on the other side of the agitator; and a transceiver, which is disposed on a body outside the toner cartridge, and outputs an emitting signal to the reflective region through the light-permeable region, wherein the reflective region reflects the emitting signal to generate a reflective signal received by the transceiver through the reflective region, wherein the first cleaner, which is rotating, intermittently cleans the light-permeable region, which is fixed; and the second cleaner, which is rotating, intermittently cleans the reflective region, which is fixed.

An image forming apparatus includes an apparatus body, an image bearing member, and a process unit attached to the apparatus body. The process unit includes a frame including a storage portion configured to store developer, a developer bearing member configured to supply developer to the image bearing member to develop an electrostatic latent image. and a circuit board attached to the frame. The circuit board includes a light emitting portion configured to emit light, and a light receiving portion configured to receive the light emitted from the light emitting portion and having passed through an interior of the storage portion.

A toner level detector includes a toner cartridge, an agitator, a reflective region, a first cleaner, a second cleaner and a transceiver. The toner cartridge stores toner, and has a light-permeable region. The agitator rotatably disposed in the toner cartridge agitates the toner. The reflective region is disposed on the agitator. The first cleaner is disposed on the agitator. The second cleaner is disposed on the toner cartridge. The transceiver disposed on a body outside the toner cartridge outputs an emitting signal to the reflective region through the light-permeable region. The reflective region reflects the emitting signal to generate a reflective signal received by the transceiver through the reflective region. The rotating first cleaner intermittently cleans the fixed light-permeable region, and the fixed second cleaner intermittently cleans the rotating reflective region.